Interdisciplinary assessment of complex regional water systems and their future evolution: how socioeconomic drivers can matter more than climate

Abstract

Modeling of future water systems at the regional scale is a difficult task due to the complexity of current structures (multiple competing water uses, multiple actors, formal and informal rules) both temporally and spatially. Representing this complexity in the modeling process is a challenge that can be addressed by an interdisciplinary and holistic approach. The assessment of the water system of the Crans-Montana-Sierre area (Switzerland) and its evolution until 2050 were tackled by combining glaciological, hydrogeological, and hydrological measurements and modeling with the evaluation of water use through documentary, statistical and interview-based analyses. Four visions of future regional development were co-produced with a group of stakeholders and were then used as a basis for estimating future water demand. The comparison of the available water resource and the water demand at monthly time scale allowed us to conclude that for the four scenarios socioeconomic factors will impact on the future water systems more than climatic factors. An analysis of the sustainability of the current and future water systems based on four visions of regional development allowed us to identify those scenarios that will be more sustainable and that should be adopted by the decision-makers. The results were then presented to the stakeholders through five key messages. The challenges of communicating the results in such a way with stakeholders are discussed at the end of the article.

MontanAqua: Tackling Water Stress in the Alps: Water Management Options in the Crans-Montana-Sierre Region (Valais)

“…Moreover, stakeholders representing very different interests elaborated a common vision as a basis for future sustainable regional development (target knowledge). Based on these assessments, strategies for sustainable water management were developed (transformation knowledge)(for more details see Reynard et al 2014, Schneider et al 2014.…”

Assessing the sustainability of water governance systems: the sustainability wheel

“…Research on possible future situations was based on visioning techniques, modeling, and calculations (Reynard et al 2014). In a participatory process with local stakeholders (group RegiEau), we developed four future visions that encompass stakeholders' different priorities of how their region should develop (regional development, infrastructure, and institutional reforms); the fourth vision (Vision RegiEau) represents a consensus of the participating stakeholders.…”

“…These visions were then translated to water use scenarios as a basis for simulating future water demands (see Bonriposi 2013). For modeling future water use, as well as resource availability, we used International Panel on Climate Change (IPCC) A1B climate change scenarios (CH2011 2011) (see also Huss, Voinesco, and Hoelzle 2013;Reynard et al 2014). …”

“…Costs, risks, and benefits of water are very unequally distributed in the region. For instance, the water richest commune (Icogne), with just a few hundred inhabitants, can use more than 50% of the water resources available (Reynard et al 2014). Not only does this provide relief from any water scarcity problems, but it has also enabled Icogne to grant hydropower concessions and consequently to collect considerable amounts of water interest rates (Schneider, Buser, and Graefe, forthcoming).…”

Simulating past changes in the balance between water demand and availability and assessing their main drivers at the river basin scale

“…Therefore, they need to be based on a thorough understanding of each region's exposure and sensitivity to climatic and anthropogenic pressures. Vulnerability to climate change is not only a consequence of a system's exposure to climatic variations but may be due to a combination of biophysical impacts of climate change and of anthropogenic pressures (Farley et al, 2011;March et al, 2012;Reynard et al, 2014). Understanding vulnerability of river basins to climate change thus requires a quantitative assessment of water demand and availability, and an appropriate representation of the inter-actions between water uses and resources (including storage and regulation facilities).…”